An Electromagnetic Pulse (EMP) has captured the attention of both preppers and fiction writers. The general concept of an EMP is an explosion which causes a burst of electromagnetic energy.
This has the capability of destroying electronic equipment, usually by causing a high voltage current to run through it. As such, this could potentially affect anything using electricity, from cellphones to whole electrical grids.
So much fiction has been written about EMPs that some mistakenly dismiss the whole idea. In reality, the most natural kind of EMP happens every day — a lightning strike. It’s powerful and destructive, but it’s limited in its area of effect. In fact, having a localized effect is characteristic of most EMPs. One exception is a CME, which can have a global effect.
Coronal Mass Ejections (CMEs) are bursts of magnetic field from the sun. They happen routinely, roughly three times a day, but they are usually too small to affect the Earth. They are closely associated with solar flares and sun spots, but they aren’t quite the same thing.
While odds are small that major CMEs will happen in our lifetime, they will happen eventually. One huge CME, now called the Carrington event or the solar storm of 1859, already hit the Earth. Telegraph systems went down, in some cases throwing sparks or shocking the operators.
Another such CME was emitted from the sun in 2012, but it missed us. If it had hit, it would have done some tremendous damage to our electrical systems and our society, which has become much more dependent on electricity than it was back in 1859.
The damage would also be global, causing some scientists to estimate that recovery in the United States from a Carrington event would take four to ten years, depending on the severity. Such a recovery is also estimated to cost a half a trillion, even up to 2.6 trillion, and that’s just for the United States. As a pessimist, I prefer to think the scientists are underestimating — it’s better to be prepared.
The good news about CMEs is that they take days to reach the Earth, and scientists always have their eyes on what’s going on with our sun. If it is a typical Carrington event, you may have as many as two days to prepare, and there are ways to protect your personal electrical equipment (though you can be sure the grid is going down thanks to the damage this would cause all transformers).
You’ll have no such warning with an EMP. While less likely than a CME, which will, given a long enough amount of time, eventually hurt the Earth, the EMP most worry about is fueled by a nuclear explosion, which is more specifically called an HEMP, and is therefore entirely dependent on whether human beings decide to use it or not.
All nuclear explosions give off electromagnetic radiation. The theory is if a nuclear weapon is set off at a high enough altitude, the radiation will become trapped in the Earth’s magnetic field and wreck it to varying degrees.
HEMP stands for high-altitude magnetic pulse. As of now, the theory behind this has not been tested, so the effects are not certain, but it would likely be significant enough for you to need to rely on your prep.